Life Expectancy in America: Then and Now

Today, Americans live about twice as long, on average, compared to when the Declaration of Independence was signed. Back in 1776, life expectancy was estimated to be around 35 to 40 years. Yet, if someone managed to survive childhood, they often lived into their 60s or even 70s.

Fast forward to today, and the average lifespan now is about 79 years, based on data from the Centers for Disease Control and Prevention (CDC).

The remarkable increase in lifespan over the centuries can largely be tied to fewer deaths in infancy and a reduction in infectious diseases, according to various researchers. Advances in sanitation, access to clean water, nutrition, vaccination, and healthcare have all played a role in bringing down mortality rates.

“A lot of this disparity stems from the very high infant, childhood, and maternal mortality rates that existed in the past,” explains Dr. Omer Awan, a physician and professor at the University of Maryland School of Medicine.

“Childbirth was perilous, and without antibiotics and vaccines, many infectious diseases—like measles, smallpox, and pneumonia—could be fatal,” he adds. “Now, with improved sanitation, clean water, vaccines, and antibiotics, we’ve seen a significant extension of life expectancy.”

Moreover, advancements in the treatment of chronic conditions such as high blood pressure, cancer, and diabetes have equally contributed to longer lives, as highlighted by the Harvard-trained doctor.

The CDC has noted that better prevention and treatment of high blood pressure has played a vital role in lowering deaths from heart disease and stroke, which are two leading causes of death in the U.S.

Dr. Mia Kazanjian, a Stanford-trained radiologist with a focus on longevity, attributes the shorter life expectancy in earlier centuries to poor sanitation, inadequate hygiene, and limited medical treatments. “Many infants and children fell victim to infections like dysentery, diphtheria, and pneumonia,” she notes. If kids made it to adulthood, they faced risks from diseases such as tuberculosis and cholera.

Key Public Health Milestones

Dr. Kazanjian points out several crucial advancements that contributed to the improvements in life expectancy, including the establishment of municipal water systems that provided cleaner drinking sources. “The first sewer system networks were built in Brooklyn in 1857,” she says. “This allowed people to drink clean water and properly dispose of waste, and indoor plumbing became more common.”

Understanding disease began to improve as well, leading to the development of public health measures aimed at minimizing risks. By the late 1800s, the acceptance of germ theory transformed medicine and public health, setting the stage for better hygiene practices.

Legislation also had its part to play. “The Federal Quarantine Act of 1878 enabled the government to prevent the spread of infections from abroad, like yellow fever,” Kazanjian explains. “Then in 1906, the Pure Food and Drug Act was passed, which set food safety regulations.”

By 1900, average life expectancy had already climbed to about 49 years. A major leap in lifespan occurred with the advent of vaccines and antibiotics aimed at preventing and treating diseases.

Dr. Kazanjian mentions that from the 1940s onward, antibiotics like penicillin became widely used, and by 1950, life expectancy had hit around 68 years. From the mid-20th century until 2014, life expectancy generally continued to rise primarily due to growing medical knowledge about preventing heart disease and stroke.

Public health initiatives targeting smoking cessation further decreased deaths from lung cancer and heart disease. “Cars became safer and car seats became standard,” she adds.

Recent advancements in emergency care and trauma services have significantly reduced fatalities from serious injuries. In addition, newer medications for cardiovascular disease and cancer have also contributed to increased longevity.

Current Challenges in Longevity

Today’s focus on longevity is shifting toward preventing chronic diseases instead of merely surviving childhood illnesses, notes Dr. Nneoma Oparaji, a medical expert with specialization in lifestyle and internal medicine. “The next goal could be less about living longer and more about living healthily for an extended period,” she says.

Dr. Kazanjian observed fluctuations in life expectancy between 2014 and 2026, crediting some declines to rising deaths among young adults from drug overdoses, particularly related to the opioid crisis, as well as suicides and alcohol-related causes.

Moreover, the COVID-19 pandemic has led to a notable decrease in life expectancy, with over two years lost between 2019 and 2021 before it started to recover, according to CDC findings.

While life expectancy has improved since the pandemic, it still falls short compared to other wealthier nations. This is largely due to higher mortality rates associated with chronic diseases, substance abuse, and preventable factors, as reported by KFF.

Obesity continues to be a growing issue, contributing to increased rates of cardiovascular disease, diabetes, and cancer. “What’s especially alarming is the rise in childhood obesity,” Dr. Kazanjian points out.

Changes in cancer trends are also affecting younger adults, as indicated by data. “My generation, the millennials, is seeing an unprecedented rise in young adult cancers, particularly of the colon and breast,” she adds, citing lifestyle factors like sedentary habits, poor diet, alcohol use, and smoking.

To improve lifespan, Dr. Kazanjian aims to heighten public health awareness about what constitutes a healthier lifestyle. “We need to move more, follow a whole food, plant-based diet, get enough sleep—around seven hours—and have regular screenings while avoiding toxins like alcohol and cigarettes,” she concludes.